Internal combustion engines are marvels of engineering — especially the efficient, sophisticated and powerful engines found under the hood of Mercedes-Benz vehicles. Even if your car has a cutting-edge hybrid system, the engine still burns gasoline, and it’s the spark plugs that make it happen. They create a perfectly-timed spark that detonates the air/fuel mixture inside the engine’s cylinders. The resulting explosions create the power that moves your car. Here are five things you’ll want to know about how spark plugs work in your car, and how to properly maintain them.
Just like the brake pads, tires, air filters and other parts of your vehicle, the spark plugs are considered “wearable” components. That means they’ll work for a certain amount of time, but eventually wear out and stop working as intended. That means you’ll have to replace the spark plugs occasionally on your vehicle for reliable performance.
Over time, the electrodes on your spark plugs will erode. Eventually, the gap between them will grow too large for a spark to reliably fire across the gap. Carbon deposits can also build up on spark plugs over time, preventing a spark from firing correctly. For reliable performance on your vehicle, you’ll want to have the spark plugs replaced before that happens.
Crack open your vehicle’s owners manual, or speak with a technician who can look up the service schedule for your particular Mercedes-Benz vehicle. For example, the spark plugs in a 2014 Mercedes-Benz E-Class should be replaced every 6 years or 60,000 miles, whichever comes first. If you can’t locate your owner’s manual, just give us a call!
Once again from the 2014 Mercedes-Benz E-Class owner’s manual, “Severe operating conditions (frequent starting and stopping, excessive idling, sustained fast highway driving) may call for spark plugs to be replaced correspondingly sooner.” We don’t have to tell you that frequent starting and stopping, excessive idling and sustained fast highway driving perfectly describes so many Southern California drivers. If you’re nearing the mileage interval for your spark plugs, and you’re stopping by for a different service, mention this to a technician. We can quickly take a look at your spark plugs and measure the gap to determine if they’re good to go or need to be replaced earlier.
If your spark plugs aren’t working, your engine may be difficult to start. If there is no spark in the cylinders, the engine won’t be able to detonate the air/fuel mixture and won’t turn over.
But, if your engine is running but a single spark plug isn’t firing consistently, this can also cause problems. The gasoline in that cylinder won’t get burned up, and will instead flow into the exhaust system. This can damage the catalytic converter.
If your spark plugs are no longer firing consistently, you may notice sluggish acceleration, misfiring and reduced fuel economy. Another tell-tale sign of bad spark plugs is black smoke coming from your vehicle’s tailpipe. When unburned gas exits the exhaust system, it leaves as black smoke and may even smell of raw gasoline. This is often caused by spark plugs that aren’t firing correctly.